//Main Intruction the application of std::bind And std::function
#include<iostream>
#include<functional>
using namespace std;

class AddTwoNums
{
public:
    AddTwoNums(int a,int b):_a(a),_b(b){}
    int Sum(){return _a+_b;}
private:
    int _a;
    int _b;
};



int main()
{
    AddTwoNums add(1,2);
    auto f1 = std::bind(&AddTwoNums::Sum,&add);
    cout<<f1()<<endl;
    return 0;
}